LeetCode——714. 買賣股票的最佳時機含手續費
阿新 • • 發佈：2020-12-18
10.24
1
今天完成了Javaweb和資料庫連線，課程錄入的程式碼
aaa.jsp:
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
<style>
.a{
margin-top: 20px;
}
.b{
font-size: 20px;
width: 160px;
color: white;
background-color: greenyellow;
}
</style>
</head>
<body>
<%
Object message = request.getAttribute("message");
if(message!=null && !"".equals(message)){
%>
<script type="text/javascript">
alert("<%=request.getAttribute("message")%>");
</script>
<%} %>
<div align="center">
<h1 style="color: red;">課程資訊錄入</h1>
<a href="index.jsp">返回主頁</a>
<form action="${pageContext.request.contextPath }/addServlet" method="post" onsubmit="return check()">
<div class="a">
課程名稱<input type="text" id="name" name="name"/>
</div>
<div class="a">
任課教師<input type="text" id="teacher" name="teacher" />
</div>
<div class="a">
上課地點<input type="text" id="classroom" name="classroom" />
</div>
<div class="a">
<button type="submit" class="b">保 存<tton>
</div>
<tr>
<td>學歷：</td>
<td>
<input type="radio"name="degree"value="專科">專科
<input type="radio"name="degree"value="本科"checked>本科
<input type="radio"name="degree"value="碩士研究生">碩士研究生
<input type="radio"name="degree"value="博士研究生">博士研究生
<input type="radio"name="degree"value="其他">其他
</td>
</tr>
</form>
</div>
<script type="text/javascript">
function check() {
var name = document.getElementById("name");;
var teacher = document.getElementById("teacher");
var classroom = document.getElementById("classroom");
//非空
if(name.value == '') {
alert('課程名稱為空');
name.focus();
return false;
}
if(teacher.value == '') {
alert('教師為空');
teacher.focus();
return false;
}
if(classroom.value == '') {
alert('上課地點為空');
classroom.focus();
return false;
}
//教師
if(teacher.value != '王建民' && teacher.value != '王輝' && teacher.value != '劉丹' && teacher.value != '劉立嘉' && teacher.value != '楊子光'){
alert('教師名稱錯誤');
return false;
}
//教室
if(!/^基教/.test(classroom.value) && !/^一教/.test(classroom.value) && !/^二教/.test(classroom.value) && !/^三教/.test(classroom.value)) {
alert('上課地點錯誤');
return false;
}
}
</script type="text/javascript">DBUtil:
package DBUtil;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
public class DBUtil {
public static String db_url = "jdbc:mysql://localhost:3306/test?serverTimezone=UTC";
public static String db_user = "root";
public static String db_pass = "chenhan";
public static Connection getConn () {
Connection conn = null;
try {
Class.forName("com.mysql.cj.jdbc.Driver");
conn = DriverManager.getConnection(db_url, db_user, db_pass);
} catch (Exception e) {
e.printStackTrace();
}
return conn;
}//end getConn
public static void close (Statement state, Connection conn) {
if (state != null) {
try {
state.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
if (conn != null) {
try {
conn.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
}
public static void close (ResultSet rs, Statement state, Connection conn) {
if (rs != null) {
try {
rs.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
if (state != null) {
try {
state.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
if (conn != null) {
try {
conn.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
}
public static void main(String[] args) throws SQLException {
Connection conn = getConn();
PreparedStatement pstmt = null;
ResultSet rs = null;
String sql ="select * from mmm";
pstmt = conn.prepareStatement(sql);
rs = pstmt.executeQuery();
if(rs.next()){
System.out.println("連線成功");
}else{
System.out.println("連線失敗");
}
}
}Dao:
package Dao;
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import DBUtil.DBUtil;
import domain.Course;
public class CourseDao {
/**
* 新增
* @param course
* @return
*/
public boolean add(Course course) {
String sql = "insert into mmm(name, teacher, classroom) values('" + course.getName() + "','" + course.getTeacher() + "','" + course.getClassroom() + "')";
Connection conn = DBUtil.getConn();
Statement state = null;
boolean f = false;
int a = 0;
try {
state = conn.createStatement();
state.executeUpdate(sql);
} catch (Exception e) {
e.printStackTrace();
} finally {
DBUtil.close(state, conn);
}
if (a > 0) {
f = true;
}
return f;
}
}domain:
package domain;
public class Course {
private String name;
private String teacher;
private String classroom;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getTeacher() {
return teacher;
}
public void setTeacher(String teacher) {
this.teacher = teacher;
}
public String getClassroom() {
return classroom;
}
public void setClassroom(String classroom) {
this.classroom = classroom;
}
public Course() {}
public Course(String name, String teacher, String classroom) {
this.name = name;
this.teacher = teacher;
this.classroom = classroom;
}
}
Servlet:
package servlet;
import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import Dao.CourseDao;
import domain.Course;
/**
* Servlet implementation class AddServlet
*/
@WebServlet("/addServlet")
public class AddServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
/**
* @see HttpServlet#HttpServlet()
*/
public AddServlet() {
super();
// TODO Auto-generated constructor stub
}
/**
* @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
*/
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
request.setCharacterEncoding("utf-8");
String name =request.getParameter("name");
String teacher = request.getParameter("teacher");
String classroom =request.getParameter("classroom");
Course course = new Course(name, teacher, classroom);
CourseDao cd = new CourseDao();
//新增後訊息顯示
if(cd.add(course)) {
request.getRequestDispatcher("aaa.jsp").forward(request,response);
} else {
request.getRequestDispatcher("aaa.jsp").forward(request,response);
}
}
/**
* @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
*/
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
doGet(request, response);
}
}
2
對於程式碼中各個類的含義還不清楚，jsp中各部分的含義也不理解。
3繼續學習jsp